Automotive vehicles, especially a two-door type vehicle has a known walk-in mechanism by which a seat back of a front seat, provided at a front low, is tilted forward, while a passenger gets in and out of a rear seat of the vehicle, at the same time, the walk-in mechanism disengages a lock mechanism of a seat slide mechanism in order to adjust the position of the seat in a front-rear direction thereof, so that it becomes easy for the passenger to access to the rear seat.
Besides the walk-in mechanism, such two-door type vehicle also has a tilt-down mechanism by which the seat back of the front seat is significantly tilted forward so that, when a rear compartment of the vehicle is used as a luggage space, it becomes easy to get a luggage into and out of the luggage space.
According to U.S. Pat. No. 6,336,679B1, a vehicle seat apparatus includes a mechanism for switching between a walk-in operation and a tilt-down operation. Specifically, a first operation lever is activated in order to execute the walk-in operation, and a second operation lever is activated in order to execute the tilt-down operation.
However, according to the mechanism disclosed in U.S. Pat. No. 6,336,679B1, when the seat being in the tilt-down state is restored to its original position, it is necessary for the passenger to activate the operation lever again. Further, parts configuring the abovementioned mechanism scatter within a reclining unit, which is used for adjusting the angle of the seat back, and a walk-in mechanism or the like is not provided as a unit independently. Thus, it is limited to secure a space in which the walk-in mechanism is provided. Further, a walk-in stopper for regulating the seat back at a predetermined angle is not provided within the walk-in in mechanism, and a protruding portion provided at the side flame serves as the walk-in stopper. Thus, flexibility in design of the seat back is significantly limited.
Another mechanism of the vehicle seat apparatus for switching between a walk-in operation and a tilt-down operation has been disclosed in JP2003182416A. Specifically, the mechanism detects a case when the walk-in operation is executed and a case when the tilt-down operation is executed by detecting a position of a seat cushion by means of a sensor link.
It is based on the premise that such mechanism disclosed in JP2003182416A is applied to a double fold type seat, whose seat cushion can be moved; however, it also can be mounted to a seat whose seat cushion is not moved (a tilt-down type seat or a fixed-type seat), if the sensor link is replaced to an appropriate link by which an operation force is inputted.
According to the vehicle seat apparatus disclosed in JP2003182416A, a central axis of a walk-in stopper pin provided at the main link is not coaxial to a rotational axis of the sensor link for maintaining the walk-in stopper pin on or out of the rotation path of the pressing member. Thus, because the sensor link, which is formed in a long shape, needs to be rotated relative to the rotational axis thereof, it is necessary to provide an additional space, as a result, the size of the seat apparatus is increased.
According to the vehicle seat apparatus disclosed in JP2003182416A, the rotational axis of the main link functioning as a stopper for the walk-in operation is coaxial to a rotational axis of the sub link for unlocking the lock mechanism of the seat slide mechanism, and a rotational axis of the sensor link is not coaxial to the rotational axes of the sub link and the main link. The sensor link can be replaced to an appropriate link by which an operation force is inputted in order to move the walk-in stopper pin so as to be out of the rotation path of the pressing member. Thus, because the main link and the sub link need are rotated relative to the rotational axis, and the sensor link is rotated relative to the other rotational axis, an additional space needs to be provided, as a result, the size of the vehicle seat apparatus is increased.
A need thus exists to provide a more compact vehicle seat apparatus.